Södermanland Runic Inscription 178 or Sö 178 is the Rundata catalog number for a Viking Age memorial runestone which is located at Gripsholm Castle, Södermanland County, Sweden, which is in the historic province of Södermanland.

The England runestones are a group of about 30 runestones in Scandinavia which refer to Viking Age voyages to England. They constitute one of the largest groups of runestones that mention voyages to other countries, and they are comparable in number only to the approximately 30 Greece Runestones and the 26 Ingvar Runestones, of which the latter refer to a Viking expedition to the Caspian Sea region. They were engraved in Old Norse with the Younger Futhark.